Breech mechanism for ordnance.



No. 708,884. Patented Sept. 9,1902.

0. HDLMSTBOM; BREECH MECHANISM FOR ORDNANCE (Applidafion filed Jun. 8,1902.)

3 Sheets-Sheet I.

(No Model.)

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Patented Sept. 9, I902.

3 Sheets-Shaet 2 C. HDLMSTRTJM. BREECH MECHANISM FOR OBDNANCE.

I (Applicatimz filed Jan. 8, 1902.) (No Model.)

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No. 708,884. Patehted Sept. 9, 1902.

C. HDLMSTROM.

BBEEBH MECHANISM FOR ORDNANCE.

(Application filed. Jan. 8, 1902.) (No Model.) 3 Sheots-Sheet 3.

1 w Z'flazeaakw Jazz/Z541 UNITED STATES PATENT OFFICE.

CARL HOLMSTROM, OF GLASGOW, SCOTLAND.

BREECH MECHANISM FOR ORDNANCE.

SPECIFICATION forming part of Letters Patent N 0. 708,884, datedSeptember 9, 1902.

Application filed January 8, 1902. Serial No. 88,939. (No model.)

To all whom it may concern:

Be it known that I, CARL HOLMsTRoM, engineer, a subject of the King ofSweden and Norway, residing at Parkhead F0rge,Rollin g Mills and SteelWorks, Glasgow, Scotland, have invented certain new and usefulImprovements Relating to the Breech Mechanism of Ordnance, of which thefollowing is a specification.

This invention relates to the breech mechanism of ordnance, and hasreference more particularly to the class of such mechanism in which thebreech-block is provided with a de Bange obturator and is rotatablymounted in a swinging carrier pivoted at one side of the gun-breech.

According to one part of my invention I employ an obturator-pad havingthe minimum amount of taper, and I so mount the breechblock in itsswinging carrier that without cutting away the threads of the block orbreechchamber said block can be inserted in or withdrawn from thebreech-chamber by the swinging movement of the carrier. For this purposeI provide on the breech end of the gun or within the breech-chamber acam-path, along which a pin or projection on the breechblock or on apart moving therewith is adapted to travel, and I construct the saidcarrier of two members or parts, which are capable of movementrelatively to each other independently of the swinging movement of thesaid carrier. The outer one of such members or parts-i. e., the one thatis remote from the pivotal axis about which the carrier swingscarriesthe block. These members or parts are so arranged and the cam-path is soformed that during the time the said pin or projection is travelingalong the said cam-path the block will first be caused to travel a shortdistance in a curved path coinciding with an arc of a circle describedfrom the axis of the pivot. -It will then be caused to move a distancein an approximately straight path or in a direction to cause its threadsto be clear of the threads of the breech-chamber, and it will thencontinue its movement in a curved path coinciding with an arc of acircle described from the axis of the pivot. This movement of the blockenables an obturator with the minimum amount of taper to be employed, asaforesaid. Suitable means are provided for retaining the said members orparts of the carrier in the position they assume during this operation.

Another part of my invention has reference to the lever mechanismemployed for actuating the breech-block and its carrier in the openingand closing of the breech; and it consists in hinging to the carrier abell-crank lever, one limb of which engages with a slot in the block,the other limb being connected to a short arm projecting from thehand-lever near its fulcrum by means of a link having universal joints.

Another part of my invention has reference to the device by which thethreads of the breech-chamber are protected during the insertion of theprojectile into the gun, said device being generally termed ashot-guide.

The object of this part of my invention is to so arrange said shot-guidethat it will automatically assume its protective position as the breechis opened and will move away from such position as the breech is closed.

In order that my said invention may be clearly understood and readilycarried into efiect, I will proceed to describe the same more fully withreference to the accompany ing drawings, in which- Figure 1 is anelevation of the breech end of a gun provided with my improved breechmechanism. Figs. 2 and 3 are plans of the same, showing the breech inits closed and open position, respectively. Fig. 4 is a horizontalsection taken approximately on the line 2 2 of Fig. 1. Figs. 5 and 6 aresectional elevations showing the mechanism for turning the breech-block,the former figure representing the block locked and the latterrepresenting the block unlocked. Fig. 7 is alongitudinal section, andFig. 8 a transverse section, of the shot-guide. Figs. 9 and 10 aredetail plan views of the said shot-guide and the means employed foractuating it, Fig. 9 representing the said shot-guide raised and Fig. 10representing it lowered. Fig. 11 is a detail section taken through thelower gap of the breech-chamber on the line 3 3 of Fig. 1.

In all the figures like letters of reference indicate similar parts.

A is the breech end of the gun; B, the

breech-block; O, the obturator; D, the obturator-pad; E, the swingingcarrier, and F the actuating hand-lever.

c c are the two parts or members of the swinging carrier, which arecapable of sliding relatively to each other, the portion 6' being keyedto the vertical pivot-pin a, which is capable of turning in the lugs orbearings a a on the gun in the ordinary manner. The breech-block isrotatably mounted in the part 6 which is made of box formt'. a, with aninternal recess to receive the part c. The inner face of the part (2 isalso formed with a cavity into which the cam-grooved projection orextension A on the breech end of the gun enters to engage with a pin cprojecting from the said sliding part 6 The cam groove or path a in theprojection or extension A is curved at its ends, and the intermediateportion joining said curved ends is straight and inclined, the curvedends being arcs of circles described from the axis of the pivot-pin a.By means of this pin and cam-groove the sliding part of the carrier iscaused to move relatively to the other part 6 during the early portionof the outward-swinging movement of the carrier, whereby the block iscaused first to move in a circular path concentric with the pivot ct tofree the obturator from its seat, then in an approximately rectilinearcourse or in such direction that the threads clear the threads in thegun, then in a circular path around the pivot 64, after which the blockwill have been Withdrawn far enough to permit of its being freely swungout of the breech-chamber by the movement of the carrier about its pivotWithout colliding with the threads of the said chamber. In order toretain the sliding part in its shifted po sition as the carrier swingsthe block to and from the breech-chamber, the sliding part is furnishedwith a lug c, Fig. 4, which bears against and travels along the fixedcampiece 9 formed on one of the brackets a The angular displacement ofthe block to lock and unlock it in the breech-chamber is effected bymeans of the bell-crank lever Z) b Figs. 5 and 6, and the link or rod bconnected to the short arm 6 of the hand-lever F. The said bell-cranklever is pivoted at b to the part c of the carrier and is adapted tomove in a vertical plane. The member 5 of said bell-crank lever isfurnished with a stud or roller Z), engaging with an inclined slot Z9 inthe rear end of the block. The other member 19 of said bell-crank leveris pivotally connected with the aforesaid link or rod 19 through aball-and-socket joint b This link or rod is also pivotally connectedthrough a ball-and-socket joint I) with said short arm I) of the lever ISaid link or rod can thus participate in a vertical as well as ahorizontal movement, as required by the movement of the said bell-cranklever and the arm 6 in different planes. The inclination of theaforesaid slot 17 and the position of the bell-crank lever and of theconnecting-rod are such that when the breech-block is in its lockedposition the said slot lies approximately at a tangent or a right angleto the member I) of the bell-crank lever, so that it is in the bestposition for resisting any tendency of the block to shift angularly inthe breech-chamber, and thereby unlock itself under the stress ofdischarge of the gun, and even if any tendency then existed to turn thebell-crank lever about its pivot such tendency would be overcome by theinability of the rod 19 to change its position by reason of its lying atthe deadcenter of the movement of the crank b of the hand-lever F; butthe position of these parts is such that when the hand-lever is actuatedto unlock the block they will cause a powerful turning movement to beexerted on said block, with the result that the unlocking of the blockcan be effected with alever-handle shorter than that usually foundnecessary for affording the requisite leverage for satisfactorilyworking the breech mechanism.

G is the shot-guide, formed with bosses g g, Figs. 7 to 10, throughwhich extends a spirally-grooved rod g, the said bosses being mounted toturn in the bracket or rearward extension A. This rod is also fitted toslide longitudinally in the said bosses and is coupled by aconnecting-rod g to a crank-arm g on the lower end of the pivot-pin a,so that as the carrier swings in opening and closing the breech the saidrod will be caused to slide longitudinally, and thereby impart rotarymotion to the shot-guide in such manner as to cause it to assume theposition represented in Figs. 1, 2, 8, and 10 when the breech is closedand the position represented in Figs. 3 and 9 when the breech is open.

In some cases the aforesaid cam-surfaces for controlling the movement ofthe block may be located in one of the unthreaded gaps of thebreech-chamber, as representedin Fig. 11, and then the aforesaidcam-slot a may be dispensed with.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is-

1. In breech mechanism for guns, the combination with a swinging carrierformed of two members one of which is capable of independent movementrelatively to the other, of a block rotatably mounted on theindependently-movable member, of a projection on theindependently-moving member adapt ed to travel alonga cam-path on thegun and to impart to the block during the swinging of the carrier, amovement first in a curved path, then in an approximately straight pathand then again in a curved path, and of a stationary cam-surface withwhich another projection on the independently movable member engagesduring the swinging movement of the carrier substantially as and for thepurpose specified.

2. In breech mechanism for guns, the combination with a swingingcarrier, a block rotatably mounted thereon, and a hand-lever foractuating said carrier; of a bell-crank lever pivoted to the carrier andengaging with a slot in the block, and of a rod connecting thebell-crank lever to the said hand-lever at a point near to the fulcrumof the latter and in a manner to permit of said rod moving in both avertical and a horizontal plane, substantially as and for the purposespecified.

3. In breech mechanism for guns, the combination with a swingingcarrier, a block rotatably mounted thereon, and a hand-lever foractuating said carrier; of a bell-crank 1ever pivoted to the carrier soas to operate in a vertical plane and engaging with a slot in the block,of a short arm located near the fulcrum of the hand-lever, and of a rodconnecting the bell-crank lever to said short arm through universaljoints substantially as and for the purpose specified.

4. In breech mechanism for guns, the combination with a swingingcarrier, a block r0- tatably mounted thereon, and means for actuatingsaid block by a hand-lever; of a shotguide hinged to the gun, of asliding quickbination with a swinging carrier, a block r0- tatablymounted thereon, and means for actuating said block by a hand-lever; ofa shotguide hinged to the gun at a point below the breech and adapted toturn in a vertical plane, of a sliding quick-threaded rod engaging withcorresponding threads on the boss of the shot-guide, and of means forimparting a rectilinear movement to said quickthreaded rod as thecarrier is swung in opening and closing the breech, substantially as andfor the purpose specified.

6. In breech mechanism for guns the combination with a swinging carrier,a block rotatably mounted thereon and means for actuating said block bya hand-lever; of a shotguide hinged to the gun at a point below thebreech and adapted to turn in a vertical plane, of a slidingquick-threaded rod engaging withcorresponding threads on the boss of thehinged shot-guide of a crank on the carrier-pivot of a bar connectingsaid quickthreaded rod with said crank, substantially as and for thepurpose specified. I

In testimony whereof I have hereunto set my hand, in presence of twosubscribing witnesses, this 27th day of December, 190 1 CARL HOLMSTROM.

Witnesses:

T. SELBY WARD, WALTER J. SKEBTEN.

